(a) Field of the Invention
The present invention relates to a packet transport layer (PTL) applied passive optical network providing method.
(b) Description of the Related Art
Regarding recent communication networks, most communication services have been made into packets as the Internet has become more important, and packet transport layer (PTL) skills with great reliability have been applied to the communication networks in order to provide the voice service of the voice over Internet protocol (VoIP) and the video service of the Internet protocol television (IPTV) to the Internet in a secure manner.
The PTL type provides the entire communication service with packets in order to increase the Internet's reliability, and accurately transmits the packets on the circuit level. However, since such type guarantees packet transmission quality but is not applicable to the access network, it is not guaranteed from one subscriber end to another subscriber end and is only applicable to communication between stations.
The existing passive optical network (PON) type includes the Ethernet PON (E-PON) type and the gigabit PON (G-PON) type.
The E-PON type is appropriate for Ethernet communication configured to Ethernet switches, and the G-PON type is available for not only Ethernet but also asynchronous transfer mode (ATM) and circuit communication.
So the PON type is easily applied to the Ethernet, and is not applicable to the PTL network that requires setting a connection in order to guarantee quality.
FIG. 1 shows networks to which the existing PTL type is applied and access networks to which the E-PON type is applied.
The packets generated at optical network terminals (ONT) 20 or optical network units (ONU) 20 of subscriber ends 10, 11, and 12 are passed through an optical line termination device (OLT) 24 and are concentrated at a first concentration switch 30.
The concentrated packets are passed through a switch or a router of the metro network 100 and the core network 200 and are distributed through a second concentration switch 32.
A PTL path 400 of the metro network 100 and the core network 200 is set by a server (not shown) and managed the path state. However, only physical links of concentration channels 40, 41, and 42 and distribution channels 43, 44, and 45 are set by an E-PON server, but the channel states are not managed.
Here, the channels 40, 41, and 42 from the ONT or ONU 20 of the subscriber ends 10, 11, and 12 are concentrated at the first concentration switch 30, and the distribution channels 43, 44, and 45 are distributed from the second concentration switch 32 to other subscriber ends 13 and 14.
Therefore, when an error occurs during transport of information, it is possible to check whether the error is generated by the metro network 100 and the core network 200, but it is difficult to check whether it is generated by the access network 300 of the concentration channels 40, 41, and 42 or the access network 300 of the distribution channels 43, 44, and 45.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.